Elevator safety system



Feb. 7, 1933. D JAMES 1,896,777

ELEVATOR SAFETY SYSTEM Filed D66. 27, 1930 2 Sheets-Sheet 1 To .s/wfif/ng comaas on dawn relay.

WITNE55E5. 1 INVENTOR Henry D. James.

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Feb. 7, 1933. H. D. JAMES ELEVATOR SAFETY SYSTEM Filed Dec. 27, 1950 2 Sheets-Sheet 2 INVENTOR Henry D. fam 25.

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Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE j HENRY D. JAMES, or EDGEWOOD, rnNNsYLvANm, ASSIGNOR To wnsErINGHoUsE TRIO & MANUFACTURING COMPANY, A CORPQRATION' or PENNSYLVANIA ELEvA'ron SAFETY sYsirEM Application med December 27, 1930. Serial No. 505,086;

My invention relates to multiple-car ele vator systems and, more specifically, has relation to elevator systems whereby a plurality of elevator cars may be safely operated in a single hatchway. r

A great saving of building space is accom plished by operating a plurality of cars in a single hatchway. The practical height of buildings is limited by the floor space taken up by the elevator hatchways necessary to provide elevator service. As the height of buildings is increased, the space devoted to elevator 'hatchways makes a greater encroachment upon the floor space, and a limiting condition is reached wherein. the floor space available for productive purposes is no longer sufiicient to yield an income commensurate with the increased cost of the building.

By operating more than one car in a hatchway, it is possible to increase the elevator,

service without making further encroachments upon the useful floor space. This arrangement is especially practical in high buildings having express-elevator service to the upper floors and local service to the lower floors, since an express car'may be ositioned and operatedin the hatchway a ove each local car.

It is,'accordingly, an' object of my, invention to provide a multiple elevator system wherein a plurality of'elevator'cars may be 7 safely operated in a single hatchway.

It is also an object of my invention to provide a safety system 'for multiple elevators which will automatically maintain a predetermined minimum-space distance between the cars as they travel upand down the hatchway.

It is a further object of my invention to provide a multiple elevator system wherein the hoist motor of a car will be deenergized and its brake applied when it approaches another car in the hatchway, and wherein the safety device of. the approaching car will be applied-if it thereafter continues to approach the other car.

According to my invention, I utilize the governor rope of each car to successively open the control circuit and apply the safety device of the other car if the latter approaches nearer thana 'certain'predetermined distance.

The invention itself, however, both asto its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description ofa specific embodiment, when read inconnection with the accompanymg drawings, in which:

Figure 1 is a diagrammatic View represhown in Fig. 1;

senting a dual elevator system arranged in Fig. 3 is a view, in side elevation, ofthe pivotedijaws shown in Fig. 2; Fig. 4 "s'a sectional view, taken on line IV-IVof Fig. '5, showing a pair ofelectromagnetically movable jaws represented at B,

and B in the'system shown in Fig. 1; and

Fig. 5 is a sectional plan view, taken on line V-V of Fig. 4. Referring more specifically to the drawings, the apparatus shown in Fig. 1 comprises an elevator car C which is suspended by a hoisting cable Ca that passes over a hoisting drum D,in the usual manner. The hoisting drum D is directly coupled to the'armature EMf of a hoisting motor EM.

be provided for operating the elevator hoist motor EM'wherein the armature EM of the elevator motor is connected in a loop circuit 11, 12 with the armature G of a generator G. The generator G is provided with aseparately excited field winding GF anda cumulative series field Winding GSF.

The armature G of the I generator G is driven by means of a driving motor M, having its armature M and its field winding A variable-voltage system of control may MF connected, in shunt relation,'to a source of power designated as the supply conductors L1 and L2. The elevator motor EM has its field winding EMF connected, for constant voltage energization, tothe supply conduc-.

tors L1 and L2;

In such system, the direction and speed of rotation of the elevator hoist motor EM is controlled by controlling the direction and value of the excitation current that is supplied to the separately-excited field winding GF of the generator G. The direction of the excitation current for the field winding GF is controlled by means of an updirection relay UR and a down-direction relay DR, while the magnitude of the current'supplied to the'field Winding may be controlled by means of an intermediate-speed relay IRand a high-speed relay HR. The operation of the relays UR, DR,-IR

' and HR- may be Controlled by means of the car switclrCs that is mounted uponthe elevator car G imposition to be actuated by an attendant onthe' car. 'My safety system may, however, beutilized in conjunction with various types of elevator-control systems jaws 24 which are thereby actuated to rope-' other than that specifically disclosed. v

Mounted on the'hoistin'g-machine shaft is a brake drum 13'which is engaged by aspring pressed brake shoe 14 to stop and, hold the, An electromagnet is providedcom-' car. prising a winding 15 which is'energized to withdraw the spring pressed brake shoe 14 and release the brake whenever the hoist motorEM is operating. j Y

A governor, or safety-actuating rope 17 passes over a governor-sheave 18 at the top of the hatchway and under a weighted. and latched idler sheave 19 at the bottom of the hatchwaya The rope 17 carries. a minnie ball 21which isjreleasably received by a spring clip 22 'on'the car C, whereby it is ments up and down the hatchway.v An overspeed governor 23 is'drlyen by the sheave 18 and is connected toa pair of rope-gripping cable 25 to be unreeled from the safety drum which applies the safety Sand stops the car C in the usual manner;

, The operation of the governor rope, the overspeed governor and the safety device/is similar to the operation of corresponding elements provided in any conventional elevator system toprevent thefcar overspeeding from any*cause,-such as broken hoist cables or a defective control system.

' Suspended in the same hatchway below the elevator car G, is a second car C which is controlled-by a hoist motor and control system identical with that shown for "car C;

P The control-system for ear O isnot-shoWn,

constrained. to follow the car in its move since it is identical with that shown in connection with car C and its illustration would unnecessarily encumber the drawings.

A governor rope 31 for'car C passes over a governor sheave 82 at thetop of the hatchablyreceived'bya spring clip 35on the car Cf, whereby the-rope is constrained to follow the" car G in its movements up and down the ,Way and under a weighted idler sheave 33 at the bottom of the hatchway. The rope 31 carries a minnie ball 34 which is releasi h'atchway. An overspeed governor 36 is V driven'by the sheave 32 to actuatea pair of rope gripping v jaws manner, as set forth with reference to car. C and its associated apparatus The safety device Symountedon car C, is likewise of vent overspeeding when a safety cable is unreeled from the safety drum. Forthis purpose, the safety cable 38 is governor rope 31 of car C. It willbe apparent thatyin the event of overspeeding of car C from any cause,

trip its rope-grlppmg aws 37 to grip the governor rope 31 and apply the safety device 7 j 17 and- 31 may also be utilized to prevent collisions S in the conventional manner. a

In order that the governor ropes attached to the the governor '36 Will- 37 in the conventional '7 theconventional type which is actuated'to 1 grip-the guide rails and stop the car-to-pre; v

betweencars, the governor rope attached to each car passes-through between a pair ofbrackets B or B and apair of pivoted jaws A orA mounted on each other car. Normally,' the ropes move freely through 'the brackets 'B or B and ithe jaws A or AZ and thecars mayassume various relative positions in their'movements up and down the hatchway. Securedtothe governor rope 31 of the lower car C",

V at .a predetermined spaced distance above the car, isa small wedge attachment 41 which is adapted to pass freely through the brackets B and to' separate the pivoted'jaws A on the upper car C when the latter approaches the lower, car. 4 A similar wedge attachment 42 is attached to the governor cable 17 below car'C. v

When the ropeBl carries the wedge attachment 41 between thejaws A, it causes them to be opened and associated contact members'43 to be disengaged. The specific structure of the pivoted jaws is clearly shownin Figs. 2 and 3, from which it may be seen that a biasing spring 44 normally holds the I jaws closed and the contact members 43 engaged. A slidably mounted spring-pressed latch 45 engages a detent 46 on the side of one of the jaws A. A stop pin-47 limits'the' movement of the other j aw, and jthe 'springpressed latch 45 holds the'jaws open and the contact members 48 separated after the passage of the wedge attachment untilthe de vice is manually'reset. v V r The disengagement of the contactmembers 43 interrupts the ma n control circuit, which extends therethrough, and thereby deener-' gizes the hoist motorEM of the upper car C and causes the'machine brakes 13, 14 to be applied. This operation must occur only trol circuit when the cars are moving up wardly, contact members av on the relay UR are connectedin Wlth.

parallel there- In order to apply further retarding force,

in the eventthat the first operation is not effective, a large stop ball 46 is attached'to the governor rope 17 of car C, at such position below the car that it willengage the bracket B on car C after the wedge elon rope 31 has entered the j aws A on car C. If the opening of the contact members on the jaws A is not effective to check the downward motion of the car C by deenergizing the hoist motor and applying the machine brake. and the car continues to move downward at a higher velocity than car C and continues to approach the latter, the stop ball 46 will engage the bracket B on the car C. The

continued movement of the car then pulls,

the minnie ball 21 from the spring clip 22 on the car C,unreels the safety cable 25 from the safety drum and applies the safety device?) to grip the guide rails and retard the downward movement of the car 0.

In order to prevent the corresponding stop ball 51 on governor rope 31 from engaging the bracket 13 on car C an d applying the safety device on the lower or leading car C, an

electromagnet 52 is provided thereon for moving the bracket toan ineffective position.

The electroma net 52 is connected into the energizing circuit of down relay DR- of car and isJtherefore, energized wheneverthe car is moving downwardly. e The control system of car Cis ident i with that shown for car C, andthecontact members of its pivoted jaws and the electromagnet of its bracket device have a similar relation to its control circuits, exceptthat the parallel shunting contacts for rendering its pivoted A ineffective are on the down-direction relay instead of on the updirection relay, and the electroinagnet, associated with bracket device B, is in series with the energizing circuit of the up relay instead of in series with the down relay, as

indicated by the legends on the drawings.

As shown in Figs. i and 5, the specific structure o the bracket device comprises a base plate 61 which presents upturned spacing projections 62 and 63 ant guide-pins 6-iand 65 integral therewith. Roller guides 66 and r 67 are pivotally mounted on each side of the tromagnet and 3.

base plate 61. A pairof bracket members B rest on the base plate 61 and are held in place in slidable relation thereto by theelecstructure 52" which is secured in spaced relation to the base plate by bolts or screws 72. The outer extremity of each bracket member B is of hook formation, and the inner extremity of each is provided with an opening through which av-bracket shaft or rod 73 extends in'transverse. relation to the base plate. 1

An armature. member T l is pivotally mounted on a shaft 75 whichalso carries cranks 7 6 thateugage the endsof the bracket shaft 73 by slotted connections., B'iasing springs 77 are mounted in compressedrelation between the bracketlshaft and stop mem bers 78 rising from the base plate 61. The

tension of the springs'Z'Znormally urges the bracket'members B outwardly andthe guide rollers 66 and 67 engage cam surfaces 79 on the sides of the bracket members 13 to force them together in juxtaposed relation.

When the bracket members'are in closed position the, governor ropes and wedge attachments can pass freely through the opening presented by-the outer extremities of the bracket members. 1 The stop balls, however,

arelarger and cannotypass throu 'h the cona V tracted bracket members. It is to be noted that the bracket :devic e and the associated governor rope and stop ball are shown 4 and 5 on a much smallerscalethan is used in representing the plvoted-jaws, governor rope and Wedge attachment 1n Figs. 2

When the electromagnet 52 of the bracket d vice is energized, the armature 74 and crank members 76 are rotated clockwise, and the bracket 13. are thereby retracted to the left. As they move to the left, the brackets are separated by the guide pins 65 and 66 and are opened to such an extent that the ball 51 can pass freely therebetwee Y My invention is best understood, however, when considered with reference to'an assumed operation thereof. j

Assuming that the cars Cand C are standstop ing at their respective lower terminals, the

operator of car C may start his car up by moving the car switch CS counterclockwise. As the switch engages itsfirst contact member, on the right-hand side, its up relay UR is energized. 1 l

The circuit by which the relay UR is enerized may bet-raced from the main-line conductor L1, through conductors 91 and 92,

thence, by way of contact members 43. on the pivoted aws A and conductors 102 and 103, to the first contact member 104 of the car switch Cs. The circuit continues, through the bridging segment of the switch to'its .rst contact member on the right-hand side, thence, by way of conductor 106, to the windT ing of relay UR, and, by way of conductor-s 107, 108, 109 and 110, to the other line con ductor'L2. s

The relay UR, being energized, pulls up its'armature to close its contact members a, b, c, and cl. Contact members a complete a shunt circuit-around the contact members 43 on the pivoted jaws A by way of conductors 91, 111 and 102 whereby an energizing circuit for relay thereafter maintained independently cf the position of the pivoted jaws A. Contact members and 0 completetan energizing circuit for the independently excited field winding GF of the generator,.wh1ch may be traced from conductor L1, by way: conductors 91 and 112, through V the contact members c'ot relay UR, conductors 113 and 11 i, field winding GRconductors 115 and 116, contact members 6 of relay UR, thence, by way of conductor 11'4",resistors R1 and. R2,. and conductor 118, to main-line conductor L2. The field winding GF of the generator G is now energized, and the generator energizes the hoist motor EM to run in the proper direction to raise the car.

The contact members d of relayv URcornplete a circuit for the-brake winding 15, and the brake 13, 14 is now released'to permit the carto move freely. The? circuit for the brake 'may be traced from the main-line conductor L1 through conductors91 and 121, brakewinding 15, conductors 122, cont-act member i cl of relay UR and thence, by way of conductors 108, 109 and 110, to main-line con- 7 way ofthe contact members 43 on the ductorL2. a v

a As the car operator continues the movement of the car-switch CS in a counter-clockwise direction, a circuit is completed for operating the car at an intermediate speed,

7 at a higher speed;

T 0 cause the car to travel at full speed, th car switch CS may be moved to its last position in the counter-clockwise direction where in it causes the energization 'of the high speed relay HR through a circuit extending from the line conductor L1 to the bridging segment of the car switch CS, as pre-' viously traced, thence, by way of the third and last contact member on the right-hand side of theswitch and the conductor 131, to the winding of the relay HR, thence, by way Assume now of conductors 125, 126 and110, to the other line conductor L2.

The energization of the high-speed relay 7 HR and the closing of its contact members serve to shunt the resistor section R2 fromthe circuit previously traced for the field wind ing GF, thereby allowing full linevoltage to be applied to the winding GF to cause the car to travel at high speed.

' The operator of car up at any time after the car G has departed,

C may start his car 7 and he accomplishes this by moving his car I switch CS counter-clockwise and operating the associated control system in a manner 1 1 similar to that set forth abovewith reference to car C. The only diil'erence in the operation of starting car C upward is apparent from the legends applied to the drawings, Since the electromagnet 182 of the bracket device B on car C is connected in series with the up relay, it will be energized to withdraw the bracket members B to ineffective position; Since the contact members 7133 on the pivoted jaws on car C are shunted'by contacts on the associated down relay, they will not be shunted when the caris started up. v

When the cars C and G are moving up the hatchway, each'governor rope is constrained to move in accordance with the movements of the car to which each is releasably connected by its minnie ball and the spring clip on the car.

travels at a higher velocity than car 0, or

that car C stops and is approached" by car The wedge attachment, 42 on the governor rope 17 of car C will pass freely through the brackets B on car C, and the'wedge 41 on the governor rope 31 will pass freely through the brackets B on car C, since the openings therebetween "are always large enough to permit the free passage of, the wedge members.

that, for some reason, car C 1 too As the car C continues to'approach the car C, the wedge attachment members 11 and 42 approach the pivoted aws Aand Af and enter therebetween to open the jaws and separate the contact members associated th re with. The separation of the contact members 43 on jaws A has no effect onthe scar C, since, as previously set forth, a cuit' was completed in parallel therewith through the contact member a of relay UR. However, the contact members 133 on the pivoted jaws A on car. C are not shunted, and, when the wedge attachment 42'causes the separation thereof, the control circuit for car C is opened, its hoist motor is deenergized and the brake is applied.

If the preceding operation is V to check the upward velocity of car G and it continues'to approach car C, the large stop ball 51 on the governor rope 81 of car G will approach the bracket B on car G, and, simultaneously, the bracket B on car C will apshunt cirnot sufficient tive position; means forconnecting each pair 7 (a of contact members into the main control 7 circuitvof the associated car, a wedge .attachv7 ment secure'd to the rope of the lower car at v such position thereon-that it will engage and open the jaws of the uppercar whenthe upper car approaches within a'predetermined distanceof the lower car tothereby deener gize the hoist'motor'andapply the machine d brake associated therewith, means for ren- 'dering said contact members on the upper car ineffective when the car is' 'traveling u' ,a wedgeatta'chment securedito the rope o p the upper car atjsuch a position thereonthat it 11 will engageand open the jaws of the lower I car when the lower car approaches within a predetermined distance of the upper car to thereby deenergize the hoist. motorand applythe machine brake associated; there 7 mm, and means for rendering the contact members on the lower car ineifective when the car is traveling down,

v 6. In combination, a pair ofelevator cars operable in a single hatchway comprising an upper car and a lower car, a safety braking device carried by each car, a governor; ropereleasably secured to each car, an overspeed governor driven by each governor rope at speeds corresponding'to the speed of the 3 associated car, rope-gripping jaws actuated byeach governor to grip the governorrope and set the safety device on the'associated car when it over-speeds, a pair of movable brackets on each car so positioned that the governor rope of'the other car normally passes freely therebetween; a stop ball secured to'the governor rope of the lowercar at such a position thereon that it willfstrike the bracket on the upper car if the lower car approaches within a predetermined distance thereof-to thereby set the safety device on the lower car irrespective of itsspeed, a stop ball secured to the governor rope of the upper'car at such position thereon that 14 it will strike the bra'cketlon the lower :car if the upper car approaches within a predetermined distance thereofto thereby set the safety device onthe upper car, irrespective of its speed, means onthe upper car for moving the associated stop brackets to inefiec tive position when said car is moving down, and means on the lower car for moving the stop brackets to ineffective position when said car is moving up, whereby the approach of one car toward the other will only actuate the safety device on the approaching car and not on the leading car. c

In testimony whereof, I have hereunto subscribed my'name this 23rd day of December,

601930. c. I v HENRY D. JAMES. 

